Refrigerating rooms and buildings



Feb. 13; 1934. F. oPHuLs REFRIGERATING ROOMS AND BUILDINGS 2sheets-sheet 1 Filed Jan. 6,' 1930 jfj INVEN TOR.

Jg* A T To haz,

RNEYS.

Feb. 13, 1934. F. oPHuLs vREFRIGERATING ROOMS AND BUILDINGS .2Sheets-Sheet 2 Filed Jan. 6, 1930 .5.55. ,5.5 :i 55.2. fsinU ao JPatented Feb. 13, 19.34

UNITED STA Tas PATENT OFFICEv 20 Claims.

The invention aims to preserve the integrity and thermal insulatingqualities of the wall structure of rooms or spaces used forrefrigeration or cold storage purposes. `Such walls are subject togradual disintegration as the result of the entrance of moisture intothe material of which such walls aremade, and at times the freezing ofthis moisture therein.

My investigations of this effect indicate that the entering moisturecomes mostly from outside the structure and not from Within therefrigerating space, even though the relative humidity within the lattermay be, and frequently is, relatively higher than the humidity of theoutside atmosphere. The wall structure is always more or less perviousto air, and the moisture seems to be carried into it by a. slow inwardseeping movement through the wall, produced by outside air pressuresexceeding the internal air pressure. Such higher outside pressures mayresult from barometric changes, or from damper adjustments in the caseof an indirectly cooled space; damper adjustments may produce asub-atmospheric pressure within an indirectly cooled space. Inasxnuch asthe temperature within the space `is normally lower than the'temperature outside the structure (that is to say, excepting possiblyduring the coldest weather) the inwardly seeping air passes inoprogressively lower temperatures within the wall structure, and afterthedew point of s uch air is reached, the water vapor therein iscondensed and left behind in the minute interstices of the structure.

Whether this theory is correct, or whether the moisture .intrudes by theeffect of osmosis or results from still some other cause, I have foundthat it can be prevented by a systematic control of the air pressurewithin the refrigerated space, and that new walls can be kept dry andold ones dried out, by maintaining the pressure within the refrigeratedspaces somewhat higher than the pressureexternally, thatl is to say, onthe opposite side of the walls. The pressure difference requi- .site forthis purpose need not be so great as to cause any inconvenience in thenormal use 4of the space or room, and my invention consists in thismethod of preserving such wall structures, as well as in apparatus forthe purpose, as below pointed out. Inasmuch as the wall structures ofrefrigerated rooms are commonly made of cellular materials, whichincludes masonry, cork, mineral wool mung, tete., 1 infer that the nove1effect I have produced results at least in part from maintaining a moreor lessconstant seepage or percolation of the inside air through `thematerial Application January 6, 1930. Serial No. 418,728

of the wall itself at a rate at least sumclent to prevent entrance ofoutside water vapor into the air-pervious structure, or entrance to sucha point therein as is cold enough to condense such vapor. Any watervapor -in the inside air, if it passes through the wall, does -notcondense for the reason that it encounters progressively highertemperatures and lower pressures in such passage. Except, usually, whlethe doors are open to give access to the refrigerating space, I usually`maintain this outward air movement lat least while the outdoortemperature is higher than the temperature of the refrigerating space.The out- 'war'd air flow can be produced by subjecting the outside ofthe insulation or wall to suction, i. e. by maintaining asub-atmospheric pressure at the outside surface of the insulation orwall, or, and preferably, by maintaining a super-atmospheric pressurewithin the refrigerated space. A difference of pressure representedbyfrom onequarter to .two inches of water is sumcient. Preferably Iprovide an automatic controller to hold the pressure difference at asubstantially constant value; this assures continual maintenance ofsufllcient pressure difference, assures the necessary pressuredifference without excess at' any time due to the fact thattheatmospheric pressure is variable, and reduces the power consumed bythe apparatus to a minimum. These and other features of the inventionappear in the various embodiments of the invention illustrated in theaccompanying drawings and hereinafter described in some detail. Y

Herein I use the term blower as including any kind of air-flow-producingapparatus that may serve the purpose indicated. Ordinarily a centrifugalblower will be found suitable.

In the accompanying drawings. Fis. 1 diagrammatically illustrates apressure system of my invention applied to a number of directlyrefrigerated rooms. Fig. 2 diagrammatically illustrates an applicationof my invention to a number of' rooms indirectly refrigerated. Fig. 3 isa diagrammatic illustration of a suction system of my invention. l

The buildingof Fig. l, of, say, brick walls 1, divided into a number ofrooms by floors 2 and lined with some suitable thermal insulatingmaterial 3, is directly refrigerated by the cooling coils 4 suspendedfrom the ceilings of the various rooms, all in accordance with commonpractice as will be recognized; the refrigerating apparatus supplyingthese coils is not illustrated. To maintain a super-atmospheric pressurewithin the various rooms, I have added a motor-driven lblower 7, theoutlet of which delivers into the header 8 which has ports or branches 9deliv- -ering into each room. As before indicated, the

super-atmospheric pressure developed thereby in the various rooms neednot be great; I contemplate that a pressure difference of say fromone-quarter to two inches of water will ordinarily give suilclent.percolation or leakage of air through the wall structure land 3.Ordinarily, I keep the blower 7 in operation at all times exceptpossibly when the outdoor temperature is lower than that within thebuilding. It will be understood that the apparatus illustrated in thelower portion of Fig. l may be installed in the building, say in thecellar at 11; I have shown this apparatus outside the structure in orderto illustrate it on an adequately large scale. To avoid the efect oiblowing relatively warm air into the refrigerated spaces, and also todehydrate this pressure-maintaining air to prevent condensation of itsmoisture within the refrigerated spaces, I pass this air through acooling bunker 14 having cooling coils 15 and 16 for example; thesecoils may be supplied from the same source as the coils "4 for example.Also, for the same purposes, the ports 9 may be so located that the airfrom them strikes or flows over the coils 4. The air from the blower 7enters the cooling bunker at the port 17, and leaves'jthe bunker at port18. A shutter 19 serves to equalize the cooling action ofthe two coils15 and 16; with this shutter in the position illustrated in full lines,the air from the blower flows first over coil 15 and then over coil 16;when the shutter is reversed g to its broken-line position, the airflows first over coil 16 and then coil 15.^ The position of the shutter19 is reversed from time to time so vthat the two coils 15 and 16 mayshare equally in cooling the pressure-maintaining air. It may bereversed automatically in various ways; for example, as the conditionsoi the two coils 15 and 16 may require, or periodically as illustrated.`

For this purpose the clock 20 is employed to' control the reversingswitch 21, which in turn controls the supply of current from the currentsource 22 to the reversible motor 23, which operates the shutter; themiddle conductor 24 being permanently connected to one of the supplylines 22 and the motor for example, the clock 20 may periodically, atdesired intervals, cause the switch 21 to connect the other of thesupply leads to either the conductor 25 or the conductor 26 and therebydrive the motor 23 in such a direction as to turn the Kshutter 19fromits full line to its dotted line position, or vice versa. The motorarmature may be connected to the reversing crank 27 through a speedreducing gearing 28: to stop the motor when the shutter has reached oneor the other of its two positions, the shaft of the crank 27 may beprovided with a limit switch 29; assuming, that the conductor 25 serves(with conductorl 24) to drive ,the motor in such a direction as to turnshutter 19 clockwise. and conductor 26 (with 24) drives the motor in theopposite directicn,the limit switch 29 will be arranged to openconductor 26 when the shutter 19 'i reaches its full linepositionyillustrated, and hold (and thereby reducing the pressure withinthat room to atmospheric) doesnot prevent the continuance of a supply ofair to the other rooms, and correspondingly a continued mainte nce of asuper-atmospheric pressure in the other rooms; that is to say, theblower and header are preferably of such capacities that the pressure atthe header side of the variousindividual branches or ports 9 serving thedifferent rooms, is held more or less substantially fixed at its initialvalue when the door 10 of one or more of the rooms is opened and therebythe pressure in that room is reduced to atmospheric. To this end, thebranches or ports 9 to the various rooms are restricted, relative to thesize of the header, and preferably they are restricted b'y shutters, asby the `sliding shutters 33 indicated in the drawings, whereby thedistribution of air to the different rooms may be controlled. Ii.'desired, shutters 32, opened by the pressure-maintaining air flow andself-closing toward the header, may be added to prevent or assur againstthe passage of air from one room to another.

The barometric regulator 34, reversible motor 35 controlled thereby, andshutter or valve 36 in the inlet to the blower 7, serve to maintain aconstant pressure rliderencc between the interior of the refrigeratedspaces and the atmosphere. In the particular barometric regulatorillustrated, a lever 40, hinged at 4l and with an adjustable weight 42at one end, y"suspends a Ibell 43, the top of which is open to theatmosphere as at port 44 while its bottom is sealed by water asillustrated and its interior 45 subjected to the pressure in therefrigerated space under its control. Where the pressure in a number ofrefrigerated rooms is controlled by a single header, as 8 for example,the interior 45 of the bell 43 may be connected to this header as hereillustrated. Changes, in the'diiferencey between the pressuresinternally and externally, cause the bell to move up, or down of course,and this moves the lever 40 and thereby serves to operate the reversingswitch 47 which, in turn, causes the motor 35 to drive in one directionor the other to open andl close the shutter 36 as needed to restore thepressure difference to the value for which the barometric regulator 34is adjusted; reversing switch 48 on the shaft of thev crank 49 (to whichthe armature shaft of motor 35 is connected through a speedreducinggearing 50) serves to 'stop the motor and shutter should the shutterreach either of its two limitpositions illustrated. Assuming that themiddle conductor 51 is permanently connected to one of the supplyconductors 22,/movement of the bell 43 downwardly servesy toconnect thisconductor to the conductor 52 whereby reversing switch 47 is so actuatedas to cause the motor 35 to move the shutter 36 toward its open positionillustrated in broken lines; likewise movement of the bell 43 upwardlyserves to connect the middle conductor 5l directly to the conductor 53so that reversing switch 47 is actuated to` cause 'the motor 35 to drivein the' opposite direction. The solenoid 54, facing one end of the lever40, serves to impose a certain amount of drag o n this lever, to preventrapid vibration of it; assuming this solenoid to be a sufliclently highresistant one, it may be connected directly to conductors 51 and 53 asillustrated. It will be apparent thereforev that the regulator 34 servesto adjust the shutter' 36 in such a manner as to maintain asubstantially constant difierence between the atmospheric pressure andthe pressure within the refrigerated rooms-excepting of course any roomthe door of which may be open, the pressure in that particular room notlimited to the detailed forms above described being atmospheric so longas its door is'o'pen.

In an indirectly cooled plant the cooling coils 55 are ordinarilylocated in al bunker as in Fig.

2, while a motor driven blower 56 circulates .refrigerating air betweenthe bunker and Athe cooling room orrooms, the air passing from `thebunker to the blower and thence through the header 56a, ports 58, thevarious rooms, ports 59, and header 60, back to` the bunker. fOrdinarily the ports or branches 58 and 59 areprovided with adjustableshutters, such as the sliding shutters 61 and 62, by the conjoint use ofwhich the amount of air passed through the various rooms, and therefrigeration in the various rooms, is regulated. In accordance with myinvention, the effective passage-ways through the ports or branches 59are so restricted (i. e., by the shutters 62 or-otherwise) as tomaintain a super-atmospheric pressure in each of the rooms; the ports orbranches 58 are then so chosen or regulated (by shutters 61 orotherwise) as, primarily, to secure the desired distribution of air tothe various rooms. 'I'he superatmospheric pressure within` the rooms ispreferably maintained automatically as before. For this purpose thebarometric regulator 63, for example such a one as is illustrated lnFig. 1, exposed at one side to the pressure of the atmosphere and at theother side to the pressure within the header 60, preferably at the endof the header remote from the cooling bunker, controls a reversingswitch 64, the v,latter in turn controlling the reversible motor'65which serves to adjust a shutter or valve 66; this shutter permits theentry of more or less air to the intake of the blower 56 from theatmosphere, and hence the more or less constant addition of air to theclosed circulating system, and Vhence controls the pressure within thesystem. A-limit switch 67 may be employed on the shaft of the crank '68as before. The pressure maintained in the header 60 may besuper-atmospheric .or subatmospheric, as will be apparent. Preferablyhowever, I so adjust the effective passageways through the ports 58 asto secure an equal distribution, or any other desired distribution, ofthe refrigerating air to the various rooms, and permanently so x them(as by permanently fixing the shutters 61 in those positions which givethe desired distribution); I then set the barometric regulator 63 tomaintain atmospheric or slightly super-atmospheric pressure in theheader 60, and regulate the refrigeration as required by manipulation ofthe shutters 62.

As before mentioned, the desired pressure difference can be obtained bya sub-atmospheric pressure outside theinsulating wall or structure. Fig.3 illustrates s uch an arrangement. Here v the main andthermally-insulating wall 70 is enclosed in a false wall 7l. and thespace between these two walls is connected to the inlet of a blower 72,so that a sub-atmospheric pressure is maintained in the `intermediatespace. A barometric regulator 73, controlling a shutter 74 in the inletpipe to the blower 72,` serves to maintain about constant the differencebetween the pressure within the refrigerated space and the pressure inthe space between the two walls 70 and 71; one side of this barometricregulator may be connected to the space between 70 and 71 asillustrated, while the other side of the regulatoris-connected to theinterior of the Vrefrigerated space as indicated at 75.

It will be understood that my invention ls and illustrated in theaccompanying drawings, `except as appears hereinafter in the'claims.

I claim: l

l. The method of preserving the wall structure of refrigerated spacesagainst the effects of moisture, which consists in maintaining'` anaverage air pressure in such space higher than the average external airpassage, and sufficiently high to prevent intrusion of water vapor intothe Wall structure, from outside the space, to a point within the wallstructure where the vapor can condense.

2. The method of preserving, against the effect of moisture therein, anair-pervious enclosing wall of a1refrigerated space, which consists inmaintaining a flow of air outward from said space through the materialof said wall at a rate sufficient to prevent the inward movement ofwater vapor through said walls to a point therein where the vapor cancondense.

3. The method of preserving, against the effect of moisture therein, anair-pervious enclosing wall of a refrigerated space, which consists inmaintaining a flow of air outward from said space through the materialof said wall at a rate greater than suficientto prevent the inwardmovement of water vapor through said walls to a point therein where thevapor can condense.

4. 'Ihe method of preserving, against the eil'ect of moisture therein,an air-pervious enclosing .wall of a refrigerated space, which consists,in maintaining a super-atmospheric pressure within the refrigeratedspace adequate to cause a flow of air outwardly through said walls atsuch a rate as to prevent the inward movement of where the vapor cancondense.

5. 'I'he combination of porous heat insulation enclosing a space whereinthe temperature is lower than the outdoor temperature, a blowerconnected lon one side of said insulation establishing a difference inpressure between the inside of said space and the outside of saidinsulation, the pressure within the space being superior, means to varythe pressure within said space, and a pressure-sensitive ,regulatorconnected to said means and adjusted to maintain a substantiallyconstant difference between the pressures at the two sides of saidinsulation.

6. 'I'he combination of porous heat insulation enclosing a space whereinthe temperature is lower than the temperature at the outer side of saidinsulation, a blower forcing air into said space and establishing asuper-atmospheric pressure therein. means to vary the pressure withinsaid space, and a pressure-sensitive regulator for said means subject tothe air pressure of the space enclosed by said insulation and the airpressure outside said insulation and adjusted` to `maintain asubstantially constant difference between the air pressure of saidspaceand the 140..

sure of the space enclosed by said insulation and l the air pressureoutside said insulation land connected to said means to control thelatter and adjusted to maintain a substantially constantsuper-atmospheric pressure in said space.

8. The combination of porous heat insulation enclosing a plurality ofseparate spaces wherein the temperature is lower than the outdoorternperature, a header, having a port to serve each of said spaces, ablower maintaining super-atmospheric pressure in said spaces, saidheader being connected to said blower for the production of an air flowbetween said spaces and the blower, means to vary the pressure in saidheader, and a pressure-sensitive regulator for said means connected tosaid header and adjusted to maintain a predetermined pressure therein.

9. The combination of porous heat insulation enclosing a plurality ofseparate spaces wherein the temperature is lower than the outdoortemperature, a header having restricted ports serving the said spaces, ablower forcing air into said spaces, means controlling the pressure insaid header, and a pressure-sensitive regulator controlling said meansand connected to said header and adjusted to maintain a predeterminedpressure therein.

10. The combination with porous heat insulation enclosing a space, andmeans therein to reduce the temperature therein, of a blower to forceair into said space to maintain a superatmospheric pressure thereinadequate to cause a flow of air outwardly through said insulation at arate substantially suicient to prevent the inward movement oi watervapor through said insulation to a point therein where the Vapor cancondense.

11. The combination with porous heat insulation enclosing a space, andmeans in said space to reduce the temperature therein, of a blower, andmeans providing a passageway for leading air from said blower to saidspace to maintain a superatmospheric pressure therein adequate to causea flow of air outwardly through said insulation at a rate substantiallysufficient to prevent the inward movement of water vapor through saidinsulation to a point therein where the vapor can condense, the outletfrom said passageway being so located that the air passing therefrompasses over the iirst mentioned means.

l2. The combination with porous heat insulation enclosing a space andmeans to reduce the temperature therein, of a blower to force air intosaid space to maintain a superatmospheric pressure therein adequate tocause a flow of air outwardly through said insulation at a ratesubstantially suiiicient to prevent the inward movement of water vaporthrough said insulation to a point therein where the vapor can condense,and means to cool the air forced into said space by said blower.

13. The combination with porous heat insulation enclosing a space andmeans to reduce the temperature therein, of a blower to force air intosaid space to maintain a superatmospheric pressure therein adequate tocause a ilow of air outwardly through said insulation at a ratesubstantially suiicient to prevent the inward movement of water vaporthrough said insulation to a point therein where the vapor can condense,and dehydrating means, the air of said blower being passed through saiddehydrating means.

14. The combination with porous heat insulation enclosing a space andmeans therein to reduce the temperature therein, of a blower to forceair into said space to maintain a super-atmospheric pressure thereinadequate to cause a flow or air outwardly through said insulation at arate substantially sufiicient to prevent the inward movement of watervapor through said insulation to a point therein where the vapor canccndense, an air cooler, means for carrying the air of said blower oversaid cooler, and means for reversing the direction of the iiow of saidair over said cooler from time to time.

15. The combination with porous heat insulation enclosing a space andmeans therein to reduce the temperature therein, of a blower to forceair into said space to maintain a superatmospheric pressure thereinadequate to cause a ow of air outwardly through said insulation at arate substantially sufilcient to prevent the inward movement oi watervapor through said insulation to a point therein where the vapor cancondense, an air cooler, means for carrying the air of said blower oversaid cooler, and means automatically reversing the direction of the ilowof said air over said cooler from time to time.

16. The combination with porous heat insulation enclosing a space andmeans therein to re- 'duce the temperature therein, of a blower to forceair into said space to maintain a superatmospheric pressure thereinadequate tocause a iiow of air outwardly through said insulation at arate substantially suilicient to prevent the inward movement of watervapor through said insulation to a point therein where the vapor cancondense, an air cooler, means for carrying the air of said blower oversaid cooler, and means periodically reversing the direction of the flowof said air oversaid cooler.

ll. The method of preserving, against the eifects of moisture, a porouswall structure of a refrigerated space normally closed against passageof air between the space and the atmosphere except for leakage throughthe enclosing Wall structure, which consists in supplying air to saidspace from outside the space, and regulating the quantity of air sosupplied In accordance with the air pressure within said space tomaintain an average air pressure in the space slightly higher than theaverage external air pressure for the 120 purpose and with the result ofpreventing intrusion of external moisture into such wall structure.

18. The method of preserving, against the etfect oi moisture therein, anair-pervious enclosing wall of a refrigerated space normally closed [25against passage of air between the space and the atmosphere except forleakage through the enclosing wall structure, which consists inproviding for a ilow of air into said space from outside saidair-pervious wall, and regulating lsaid flow 130 in accordance with theair pressure within the space to maintain a iiow of air outward fromsaid space through the material of said air-pervious wall at a ratesuiiicient to prevent the inward movement of water vapor through saidair-pervi- 135 ous wall to a point therein where the vapor can condense.

19. The method of preserving against the effect of moisture therein; anair-pervious enclosing wall of a refrigerated space normally closed 140against passage of air between the space and the atmosphere except forleakage through the enclosing wall structure, which consists inproviding for a ilow of air into said space from'outside saidair-pervious wall, and regulating said flow in ac- 145 cordanoe with theair pressure within the space to maintain a flow of air outward fromsaid space through the material of said air-pervious wall at aratelgreater than sufficient to prevent the inward movement of watervapor through said wall 15u cordance, with the air pressure within thespace lto maintain a superatmospheric pressure within the refrigeratedAspace adequate to cause a. ow of air outwardly through said wall at sucharate as to prevent the inward movement of water vapor through saidwalls to a point therein where the vapor can condense.

FRED OPHULB.

